Wolfenstein: Enemy Territory (abbreviated as WOLF:ET, WET, and among gamers, ET) is a freeware first-person shooter (FPS) computer game, and a standalone sequel to Return to Castle Wolfenstein, created by Splash Damage.

Enemy Territory was originally planned to be released as a commercial expansion pack to the popular FPS Return to Castle Wolfenstein. However, due to problems with the single-player aspect, the multiplayer portion was released on May 29, 2003 as a freeware standalone game. In early 2004 the source code for the game logic (not the game engine) was released to the benefit of its modding community. The game's engine (Quake III) is free software/open-source.

Text taken from Wikipedia.

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